Electromechanical emergency-brake for tram-cars.



No. 673,286. Patented Apr. 30, MIL E. VON PLANTA.

ELECTBOMECHANICAL EMERGENCY BRAKE FOR TRAN CARS.

(Application filed Jan. 10, 1901.)

(No llodol.)

UNITED STATES PATENT OFFICE.

EMANUEL VON PLANTA, OF LUOERNE, SWITZERLAND, ASSIGNOR TO THE GESELLSOHAFT FUR PATEN'IVERWERTUNG DER ELEKTROMEOHAN- ISCI'IEN NOTBREMSE, (SYSTEM PLANTA,) OF BASLE, SYVITZERLAND.

ELECTROMECHANICAL EMERGENCY-BRAKE FOR TRAM-CARS.

SPECIFICATION formingpart of Letters Patent No. 673,286, dated April 30, 1901.

Application filed January 10, 1901. Serial No. 42,712. (No model.)

To all whom it may concern:

Be it known that I, EMANUEL VON PLANTA, a citizen of Switzerland, residing at Lucerne, in the canton of Lucerne, Republic of Switzerland, (whose post-office address is Morgartenstrasse 11,) have invented certain new and useful Improvements in Electromechanical Emergency-Brakes for Tram-Cars Driven by Electricity; and I do declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, which form a part of this specification. V

I have applied for patents in the following I5 countries: Switzerland on June 23, 1900; Austria, September 13, 1900; Belgium, September 14:, 1.900, and Germany, September 15, 1900.

The invention relates to an electromechanical emergency-brake'for electrically-driven 2o tram-cars. Usually in such cars the motors may act as generators when the external current is cut off while the velocity of the car is considerable, and on the completion of a short circuit the energy stored should,theoretically, bring the car to a sudden stop, since the motors are geared with the wheel-axles by cog-.

wheels. It is upon this principle that the well-known short-circuit brake is based; but owing to the momentum of the car the latter may, if no mechanical brake is pro vided, slide several meters on the rails, although the wheels are prevented from turning. In order, therefore, to enable the car to be brought to a standstill within a very short distance, the short-circuit brake alone is not suflicient, and it is necessary to combine with it a mechanical brake.

According to this invention the above-mentioned object is attained by causing skidshoes to be released by means of electromagnets on the short circuit and to drop upon the rails in front of the wheels, so that the latter will run onto the skid-shoes, whereby the instantaneous stoppage of the car will be effected.

The invention is illustrated, by way of example, in the accompanying drawings, where- Figure 1 is a diagrammatical illustration of the arrangement. Figs. 2 and 3 show detail views of the skids, and Fig. 4: is a diagrammatic illustration of the arrangement with a sanding device attached.

In connection with the two motors ct of the car is an electric circuit 1), in which there may be several electromagnets 0, only one electromagnet 0 being indicated in the drawings for the sake of simplicity. The armature dof each electromagnet c is adapted to .act as a detent to retain the system of the levers e f g, supporting the skid-block h and shoe 7c, in the position shown. The said skidblock rests freely by pins 2' upon the carrier 9, and the shoe or bottom piece is adapted to fit the groove of the rail. If now immedi- 65 ately after cutting off the supply of current to the motors the short circuit Z) be completed, the electric current generated in the motors by the momentum of the car causes the electric brake to act, and simultaneously 7o therewith the electromagnets c attract their armatures, whereby the system of levers cf 9 isreleased and the skids are caused to drop upon the rails, so that the wheels of the car, not yet being completely stopped by the com- 7 5' pletion of the short circuit, run onto the skids, whereby the car is brought to an absolute standstill. The braking of the car is therefore effected in two very short periods of time following one another immediately and allowing the car to drag only for a very short distance. In the short circuit b there may be another electromagnet Z, Fig. 4, whose armature m may be adapted to actuate a slide 'n of a sand-box 19 against the tension of the spring 0 in normally tending to close said slide, so as to cause a sufficient quantity of sand to be discharged at the moment when the short circuit is completed in order to thereby increase the adhesion of the skids upon the rails.

Having now particularly described and ascertained the nature of the said invention and armature disposed in operative proximity to said electromagnet, a skid adapted to be en;- gaged by one of the wheels of a vehicle to stop the latter, resting on one of the-rails, and a train of mechanism carrying said skid and normally engaged by the armature to maintain the skid elevated,said source of electrical energy being adapted, through said circuit, 1

as a means for braking the vehicle and simultaneously actuating said armature, sub- 10 

